Diaryliodonium salts are useful as arylating agents for a large variety of organic and inorganic nucleophiles. They have also been applied in metal-catalyzed cross-coupling reactions (Ryan, J. H. and P. J. Stang, Tetrahedron Lett. 1997, 38, 5061-5064; Zhang, B.-X., et al., Heterocycles 2004, 64, 199-206; Kang, S.-K., et al., J. Org. Chem. 1996, 61, 4720-4724; Al-Qahtani, M. H. and V. W. Pike, Perkin 12000, 1033-1036; Kang, S.-K., et al., Tetrahedron Lett. 1997, 38, 1947-1950) due to the excellent leaving-group ability of the aryl iodide moiety (Okuyama, T., et al, J. Am. Chem. Soc. 1995, 117, 3360-7). Other than these applications, diaryliodonium salts were found to play a role as oxidants for dearomatization of phenols (Moriarty, R. M. and O. Prakash, Org. React. (N. Y.) 2001, 57, 327-415; Moore, J. D. and P. R. Hanson, Chemtracts 2002, 15, 74-80; Ciufolini, M. A., et al., Synthesis 2007, 3759-3772) and as cationic photoinitiators in photochemistry (Toba, Y., J. Photopolym. Sci. Technol. 2003, 16, 115-118; Crivello, J. V., J. Polym. Sci., Part A: Polym. Chem. 2009, 47, 866-875; Crivello, J. V., Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.) 2006, 47, 208-209).
Diaryliodonium salts are also useful for the synthesis of aryl fluorides, for example, in the preparation of 18F labeled radiotracers. Aryl fluorides are structural moieties in natural products as well as a number of therapeutically important compounds, including pharmaceuticals and positron emission tomography (PET) tracers. Diaryliodonium salts are particularly useful for the nucleophilic fluorination of electron-rich arenes, a class of compounds that is inaccessible using conventional nucleophilic fluorination methods.
For at least these reasons, there is a need to develop new routes in diaryliodonium salts, particularly those having a broad range of functional groups. This application addresses this need and others.